An issue was discovered in Zammad before 6.2.0. It uses the public endpoint /api/v1/signshow for its login screen. This endpoint returns internal configuration data of user object attributes, such as selectable values, which should not be visible to the public.
{
"versions": [
{
"introduced": "0"
},
{
"last_affected": "6.1.0-NA"
},
{
"introduced": "0"
},
{
"last_affected": "6.1.0-alpha"
},
{
"introduced": "0"
},
{
"last_affected": "6.2.0-alpha"
}
]
}